The invention relates to a heat transfer device of a stacked plate construction consisting of several plates which are stacked above one another and provided with openings.
In the parent application, heat transfer devices of the initially mentioned type are described comprising: flow duct plate units with one or several side-by-side flow duct openings, which extend between two plate side areas, as well as with connection duct openings, which are arranged separately of the connection duct openings, and connection cover plate units which have connection duct openings which are arranged at least in two plate side areas, wherein the flow duct plate units and the connection cover plate units are alternately stacked on one another such that no fluidic connection exists between the flow duct opening of adjacent flow duct plate units; and such that the equal-sided ends of the flow duct openings of a respective flow duct plate unit are in a fluidic connection with one another by way of an overlapping connection duct opening of an adjacent connection cover plate unit and are in a fluidic connection with the equal-sided ends of the flow duct openings of in each case a next but one flow duct plate unit, by way of overlapping connection duct openings of adjoining plate units, These heat transfer devices of a stacked plate construction can be manufactured at comparatively low expenditures and are suitable for the separate flowing-through of at least two heat transfer fluids, in which case largely laminar flow conditions and a satisfactory heat transfer capacity are ensured.
In the embodiments explicitly illustrated and described in the parent application, the plate units of a respective heat transfer device plate stack are all of a rectangular shape. The connection duct openings extend in the form of oblong holes along the respective rectangle sides. A row of flow duct openings of a respective flow duct plate unit, which are situated in parallel side-by-side, on the end side, essentially overlaps with the whole passage cross-section of the equal-sided connection duct opening of an adjacent connection cover plate unit, the overlapping cross-section determining the opening cross section of the resulting distributor duct or collecting duct on the corresponding plate stack side. In this case, separating webs, which laterally mutually space the flow duct openings of a respective flow duct plate unit situated in parallel side-by-side, extend with their end areas transversely through the distributor duct or collecting duct.
The invention is based on the technical problem of providing a heat transfer device of a stacked plate construction of the general type described in the parent application which has particularly good fluid flow characteristics with low pressure losses and nevertheless can be implemented in a relatively compact construction.
The invention solves this problem by providing a heat transfer device of the above-mentioned type wherein one connection duct opening respectively is provided on each plate side area of the flow duct plate units as well as of the connection cover plate units, the respective equal-sided, mutually overlapping connection duct openings, by means of an exterior portion, forming a connection conduit situated outside the area of the flow duct openings, from which connection conduit, with the exception of the ones which are arranged adjacent to the ends of the flow duct openings in the respective flow duct plate units, they extend with one interior portion overlapping into the area of the equal-sided ends of the flow duct openings. In addition to the characteristics explicitly indicated in the parent application, it is specifically provided in the case of this heat transfer device that one connection duct opening respectively is provided on each plate side area of the connection cover plate units as well as of the flow duct plate units, in which case the overlapping connection duct openings of a respective plate stack side form a connection conduit situated outside the area of the flow duct openings, from which connection conduit the connection duct openings, with the exception of those which are arranged adjacent to the ends of the flow duct openings in the respective flow duct plate units, extend with their interior portion into the area of the equal-sided ends of the flow duct openings.
This means that, in contrast to the embodiments according to the parent application, the total passage cross-section of a respective distributor duct or collecting duct is not limited to the overlapping cross-section of the connection duct openings with the flow duct openings but, in addition, comprises the passage cross-section of the pertaining connection conduit which in comparison is preferably clearly larger. By the corresponding selection of the respective connection conduit passage cross-section, in the case of a given plate thickness and plate number in the plate stack for the resulting total passage cross-section of the flow duct openings which are in each case in a fluidic connection with one another, a correspondingly matching passage cross-section of the pertaining distributor duct or collecting duct can be adjusted. In addition, by means of this connection conduit formation, favorable fluid flow characteristics for the distributor ducts and collecting ducts as well as for their flowing into the flow duct openings and for the flowing out of the latter is achieved. On the whole, a compactly constructed heat transfer device of a stacked plate construction can therefore be implemented with laminar flow conditions, low velocity gradients in the flow direction and low deflection and impact pressure losses.
According to especially preferred embodiments of the invention, the heat transfer device is dimensioned such that the passage cross-section of a respective distributor duct or collecting duct formed by mutually overlapping, equal-sided connection duct openings is at least as large as the total passage cross-section of all flow duct openings which are in a fluidic connection with it. This contributes to avoiding undesirably high pressure losses.
Especially preferred embodiments of the heat transfer device are further developed to have a special optimized plate stack geometry which, on the one hand, has favorable flow and heat transfer characteristics and, on the other hand, is relatively easy to manufacture. In a further development of this heat transfer device, the plate stack is closed off on one face by a cover plate while, on the opposite face, a connection plate is provided which has connection openings to the two distributor ducts and collecting ducts respectively. In this manner, the two fluids flowing through the heat transfer device can be supplied and discharged on one plate face end in the direction of the longitudinal axis of the stack.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.